The Liebermanns are celebrating Herr Liebermann’s birthday, but their spirits are quickly dampened. First, Max reveals that he and Clara have broken off their engagement. Then that disappointing news is upstaged when a scream comes from another room. Daniel, Max’s teenaged nephew, is cutting into his arm with a knife.
Max stops the boy and treats the wound. The Liebermanns want to pretend it was an accident, but Max knows it was deliberate—and the revelation that Daniel’s back is scarred and bruised causes more worry.
Max goes to Oskar for help. Daniel’s father was a soldier; after he died in battle, Max’s sister sent Daniel to St. Florian’s, an illustrious military academy outside Vienna attended by the sons of some of Austria’s most important men. Max asks Oskar to visit the school with him to investigate the cause of Daniel’s trauma.
The headmaster is unhelpful: boys will be boys and all that, and Max and Oskar can’t speak to the students without parental permission or a warrant. The second-in-command, Becker, who teaches biology and chemistry and runs the sick room, doesn’t have much to say either.
One teacher, sent with Max and Oskar to fetch Daniel’s things from his dormitory, is more forthcoming. An artist, Herr Lang seems out of place at the school: he’s the only teacher not in military uniform. At Daniel’s dormitory, he tells Max and Oskar that the boy whose bed neighbored Daniel’s died about ten days ago. His body was found in the river in the morning; he must have gone out at night and slipped, fallen, and drowned. His name was Zelenka.
Max suddenly realizes that Daniel wasn’t just trying to cut himself—he was carving a “Z” for Zelenka into his arm. But why would Daniel try to memorialize Zelenka in such a gruesome way? And what is the meaning of the paper filled with three-digit numbers that Daniel had among his things? The boy won’t answer, but he does mutter through the questions and eventually begins yelling “I’m sorry” while rocking back and forth.
Max suspects the numbers are a code like one his father taught both him and Daniel as children, but he needs to know the book the code uses as a reference in order to decipher the message.
Investigating other leads, Max and Oskar speak with the coroner about Zelenka’s death. The boy drowned and had a blow to his head, probably from falling on something—it was a simple enough death that the coroner didn’t do a postmortem. Max accuses him of neglecting his duty, noting that the blow might not have been accidental. Max and Oskar go look at the body themselves, and note a circular wound in the palm of Zelenka’s hand. It’s identical to one that Oskar saw on another boy at St. Florian’s.
Back at St. Florian’s, Max and Oskar ask Lang about the mark. Lang admits that there is a sadistic ritual passed on amongst the boys—he thought he had put an end to it. They gather in a crypt and heat a coin in a fire, then force the burning coin into a boy’s palm. Zelenka was not tough like the other boys; he may have been tortured because he was different.
Oskar noticed a trophy at St. Florian’s engraved with the name von Bülow, his rival in the police force. Von Bülow was the investigating officer in Zelenka’s death—did he prevent a postmortem out of loyalty to his school? The commissioner is being promoted to chief of police, and von Bülow and Oskar are the top contenders for his old job, so Oskar is eager to find mistakes in von Bülow’s work. He warns von Bülow that he is reopening the investigation into Zelenka’s death.
Over billiards, Oskar asks Max why he has been glum lately—it’s not just Daniel’s behavior. Max admits that he broke off his engagement—Clara has returned the ring, and his parents are utterly disappointed. Oskar believes—correctly—that another woman plays into this.
Oskar himself has recently had a woman reappear in his life, showing up at his home. Their relationship is tense but intimate—perhaps this is the wife who left after the death of their daughter.
Max decides to confront his confused feelings and visit Amelia Lydgate—the other woman. Just as she was in telling him they should not see each other, she is blunt. When Max tells her about the end of his engagement and confesses that he is love with her, she dismisses him: “love is just a chemical,” a biological phenomenon. As he continues to express his feelings, she seems to soften—but then someone else walks into the room, and they break off their conversation.
Back at St. Florian’s, another boy is being subjected to the hazing ritual. Having received his own burn, he gets a coded note on his pillow, then wakes up another boy in the night and brings him to the crypt. Several boys are waiting: they punch the new boy in the face, leaving blood splatters on the floor, then press the hot coin into his palm.
Max and Oskar talk to Zelenka’s relatives. Only his sister is in Vienna; she says Zelenka was a painter, and asks Max and Oskar to retrieve a portrait he was working on from St. Florian’s. This gives Max an idea: if Daniel won’t talk, perhaps images will help.
He makes an inkblot on a page and asks Daniel what he sees. “Wolf,” he says. It’s the name of one of the boys at St. Florian’s—and Daniel also has a burn mark on his hand.
Oskar gets a warrant, and he and Max begin to interview the boys. Wolf says he didn’t know Zelenka, then eventually admits that Zelenka was a lousy soldier and didn’t fit in. He also warns Max and Oskar that his father is a general.
Convinced that the tightknit group of boys won’t admit to anything, Max and Oskar simply sit them down and stare at them silently, waiting for them to speak. Finally, one boy admits to finding a letter behind Zelenka’s locker one day. It was addressed to “beloved,” and included plans to run away and tell the world about St. Florian’s.
Zelenka’s death wasn’t an accident, Max says. This has turned into a murder investigation.